Use of AC impedance spectroscopy for monitoring sound teeth and incipient carious lesions

Impedance Spectroscopy as a Tool for the Detection of Occlusal Noncavitated Carious Lesions

A total 302 teeth (148 molars and 154 premolars) corresponding to 152 patients aged ≥18 years were evaluated for caries using the ICDAS (International Caries Detection and Assessment System), fluorescence (DD, DIAGNOdent) and electrical impedance (IMS, CarieScan PRO) systems. Fissurotomy and intraoral radiographs were used as the gold standard. Accordingly, 27.5% (n=84) of the teeth were classified as sound, while 26.9% (n=81) had enamel involvement and 45.6% (n=138) presented carious lesions reaching the dentin. Sensitivity (Se), specificity (Sp), and the area under the curve (AUC) were, respectively, 90.7%, 87.8%, and 0.954 (IMS); 92.4%, 92.7%, and 0.954 (DD); and 79.0%, 72.3%, and 0.756 (ICDAS). With regard to Se and Sp, there were significant differences between ICDAS and DD (p<0.001) and between ICDAS and IMS (p=0.01), but not between IMS and DD (p=0.07). In relation to AUC, there were significant differences between ICDAS and DD (p<0.001), and between ICDAS and IMS (p<0.001), but not between IMS and DD (p>0.05). The correlations between fissurotomy and each method were 88.7% (IMS), 89.7% (DD), and 77.1% (ICDAS). Within the limitations of this study, clinically, the electrical system is not useful for differentiating between sound teeth and truly incipient caries lesions by itself. The fluorescence or electrical systems are recommended with the ICDAS to detect carious lesions in their early stages.

Knowledge of undergraduate dental students regarding management of caries lesions

Objectives

Understanding of lifelong control of disease processes associated with caries and its management is an essential part of dental education. This study evaluated the dental students’ knowledge of caries diagnosis and management using the International Caries Classification and Management System (ICCMS).

Methods

A survey was conducted among undergraduate dental students at two dental schools, attending the sixth (centre 1) and seventh semester (centre 2), respectively. Medical histories, clinical images and radiographs of 12 patients were compiled as anonymous cases. For each case, a specific lesion was to be assessed. In addition, the students should determine the patient’s caries risk and select a treatment option. An expert report (consensus decision) was used as the reference standard. For statistical analysis, kappa statistics and binomial tests were used.

Results

A total of 46 students participated in this study. The percentage of agreement of responses to the reference was: centre 1: 40.7–51.3%, centre 2: 57.9–67.9%. The corresponding Kappa values were: centre 1: 0.073–0.175, centre 2: 0.315–0.432. Overall, students tended to underestimate the codes compared to the reference standard (p < 0.001).

Conclusion

Introducing systematic content about caries diagnosis and management such as ICDAS and ICCMS in the learning objectives of undergraduate dental students can be proposed. However, in order to improve diagnosis and enable a more reliable choice of treatment options, attention should also be given to the way they are didactically taught.

Near-infrared transillumination with high dynamic range imaging for occlusal caries detection in vitro

The aim of this study was to assess near-infrared transillumination with high dynamic range imaging (NIRT-HDRI) for occlusal caries detection in vitro and to compare it with visual inspection using the International Caries Detection and Assessment System II (ICDAS) and digital bitewing radiography (BWR). Sixty-one extracted permanent molars with sound or occlusal carious surfaces without severe cavitation were visually assembled. Two examiners assessed twice these surfaces independently using ICDAS, BWR and NIRT-HDRI. The latter was performed with a prototype consisting of two laser sources (780 nm), a CCD sensor and subsequent processing with image analysis software. Thresholds for carious surfaces, enamel and dentin lesions were defined for all methods. Micro-computed tomography served as the reference standard. Linear weighted Kappa analysis of the methods versus the reference at the threshold carious surface, enamel and dentin lesion revealed 0.59/0.08/0.12 for ICDAS, 0.37/- 0.06/0.58 for BWR and 0.33/- 0.01/0.51 for NIRT-HDRI. Sensitivity values at the three thresholds were 0.85/0.78/0.13 for ICDAS, 0.59/0.00/0.69 for BWR and 0.98/0.33/0.78 for NIRT. Specificity values at the three thresholds were 0.70/0.40/1.00 for ICDAS, 0.9./0.96/0.90 for BWR and 0.30/0.65/0.72 for NIRT-HDRI. Reliability analysis revealed substantial agreement for BWR and NIRT and almost perfect agreement for ICDAS. NIRT exhibited a strong ability to identify occlusal dental decay in general; however, it revealed a tendency towards overestimation. Its strength was the detection of dentin caries lesions compared with ICDAS and BWR. NIRT-HDRI seems to be a suitable method to detect hidden dentin caries as a supplement to visual examination.

Clinical performance of the near-infrared imaging system VistaCam iX Proxi for detection of approximal enamel lesions

OBJECTIVES/AIMS

Apart from the visual detection of caries, X-rays can be taken for detection of approximal lesions. The Proxi head of VistaCam iX intraoral camera system uses near-infrared light (NIR) to enable caries detection in approximal surfaces. The aim of this study was to evaluate the performance of the NIR for the detection of approximal enamel lesions by comparison with radiographic findings.

MATERIALS AND METHODS

One hundred ninety-three approximal surfaces from 18 patients were examined visually and using digital radiographs for presence or absence of enamel lesions. Then digital images of each surface were produced using the near-infrared light. Correlation between methods was assessed using Spearman's rank correlation coefficient (rs). Agreement between radiographic and NIR findings was calculated using the kappa coefficient. McNemar's test was used to analyse differences between the radiographic and NIR findings (α=0.05).

RESULTS

Moderate correlation was found between all detection methods (rs=0.33-0.50, P<0.0001). Agreement between the radiographic and NIR findings was moderate (κ=0.50, 95% CI=0.37-0.62) for the distinction between sound surfaces and enamel caries. No significant differences were found between the findings (P=0.07).

CONCLUSION

Radiographs and NIR were found to be comparable for the detection of enamel lesions in permanent teeth.